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Class Ld ^£41 

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COPYRIGHT DEPOSIT 



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Fresh Air. 



THE VENTILATION 



OF THE 



School Room, 

— BY — 

Wm. J. Baldwin, m. am. soc. c. e., 

H 
MEM. AM. SOC. MECHS. ENGS. 

EXPERT 

AND 

CONSULTING ENGINEER. 



HEATING AND VENTILATION 



{^Copyrighted, igoi.) 

PRICE, ONE DOLLAR. 



Published by the Author, 

107 W. 17TH Street. 

New York. 




[the library of 

j CONGRESS, 

Two CoHiM Received 

SEP. 25 1901 

COPVRIQHT ENTRY 

<9c^. // /q o/ 
CLASS O^OCXa. N#. 

I COP Y a 




3 ^^ 



TO 

ABRAHAM ABRAHAM, Esq. 

OF BROOKLYN, 
IN CONSIDERATION OF THE INTEREST HE TAKES 
IN THE SUBJECT. 



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IN 1897 the author published a little blue book, 
called "Data for Heating and Ventilation," 
and in its preface he promised to continue his 
efforts in a similar line at a later date, provided 
the endeavor he then made was appreciated. 

The demand and the appreciation for the "blue" 
book was greater than his anticipations, and the 
many letters asking to be remembered when an- 
other book was issued, induced him to produce a 
red hook for the year 1899, and call it "An Out- 
line of Ventilation and Warming." 

He now issues his little "white" book under 
the title of T/ie Ventilation of the School Room 
(1901) and he trusts that in the future he may be 
able to continue his work in similar lines. 

The author has the honor to be the pioneer 
x\merican writer of a book of reference on steam 
heating, etc. This book known. as "Baldwin on 
Heating" from the press of John Wiley & Sons, 
has now reached its 15th edition ; something that 
no other engineering work ever printed in America 
has attained. 

(3) 



THE VENTILATION OF THE SCHOOL ROOM. 
Perfect Ventilation ? 



T PRESUME the word "perfect" should never 
* be associated with the word "ventilation." 

What is "perfect ventilation?" 

If one lived in a tube, taking air at the bottom 
and discharging it at the top, and the air was 
taken from the top of one of the highest moun- 
tains, presumably it would satisfy the person who 
is looking for " perfect ventilation." 

Under the ordinary conditions of our lives, in 
our homes, at our business, in school, in the thea- 
tre, we have to take what we can get in the matter 
of ventilation, or more properly speaking, air^ 
fresh or foul and make the most of it for the time 
being ; and the only way we can help ourselves, is 
by simply avoiding the places, when it is possible, 
where we know the ventilation to be either very 
bad or none at all, and patronize the places in 

(5) 



6 THE VENTILATION 

which there is some systematic attempt at ven- 
tilation. 

We cannot live in tnbes, and we therefore live 
in houses, in fellowship with our kind, breathing 
the same air with them and helping to contaminate 
it, and an analysis of the air taken at the outlet 
will be a fair sample of what we breathe, each per- 
son having added his or her quota of contamina- 
tion ; the same mingling with the mass : although 
at the same time, through some properly arranged 
inlet and outlet, there may be passing a stream of 
air, the inlet presumably fresh, and the outlet 
more or less contaminated . 

This is all we can hope for while we live to- 
gether, and our effort should be to secure " good " 
or "fair" results under the normal conditions of 
human life, and not look for an ideal condition 
that is impossible to attain. This is why the 
word perfect should be omitted in a ventilating 
specification, as no one can attain it. 

I may now ask "what is ventilation?" (in 
contra distinction to "perfect ventilation" as 
quoted above.) This question may be answered 



OF THE SCHOOL. 7 

L by saying, that any means whereby the air of 
habitations can be maintained at some common 
standard of purity, can be termed "ventilation." 

The "standard" can be placed higher or lower 
as the local conditions may seem to require, or the 
persons interested can afford. 

Movements of confined air, which simply pro- 
duce a sense of cooling, must not be confounded 
j with true ventilation. 

A room or building may be well ventilated from 
a hygienic standpoint, and still be deemed uncom- 

* fortable to live in by being over or under-heated. 
If it is over-heated, the unthinking person is apt to 

• sa}^ the ventilation is bad, while as a matter of fact, 
it may be that only the warming lis improperly 

idone ; and this is why the question of warming and 
ventilating have to be considered together in all 
cold climates. 

I am not, however, going to consider the ques- 
tion of warming here, any farther than is necessary 
to properly present the question of fairly good or 
good air in habitations, schools or other inclosed 
space. 



8 THE VENTlIvATlON 

I have made tests in a hospital as to the quantity 
of air that was moving through it, and found that 
the average amount of air per bed was between 
7,000 and 8,000 cubic feet per hour. At the same 
time, the physician in charge declared that the 
ventilation of the hospital was '' abominable." 
His opinion was not based on the chemical analy- 
sis of the air. It was based on the fact that the 
room was too warm. A room receiving but 1,000 
cubic feet of air per bed might pass as "fairly 
well" ventilated provided the temperature was 
comfortable. 

I only cite the case of the physician to show how 
educated persons may err on the subject of ventila- 
tion, when the personal feelings alone are the 
instruments with which one measures the standard 
of purity. 

"What is the standard of purity at which air 
should be maintained ? ' ' The necessity for a stand- 
ard of purity implies, of course, that individuals 
contaminate the air of habitations, and that suffi- 
cient fresh air must be admitted and an equal 
amount expelled or withdrawn until the air within 



OF THE SCHOOL. 9 

the building is kept at a degree of purity very 
nearly equal to the purity of the outside air. This 
is ventilation, but it has not answered the question 
of a working standard of purity. 

The writer knows of many buildings that are 
even as yet being used as schools or places of edu- 
cation, that are almost, if not entirely, without 
ventilation in the proper sense of the term. 

The principal of a ladies' seminary in Greater 
New York, while showing the mother of a pro- 
spective pupil her institution, explained the ad- 
vantages of having large dormitories divided into 
small rooms, with partitions that did not run to the 
ceiling, by saying, *'We get the most perfect ven- 
tilation thereby — a free movement of the air from 
one room to the other ; " and when it was suggested 
that the air of one room was probably no better 
than the air of the other room, she explained, that 
"As soon as the pupils retired, they covered their 
heads with the bed clothing, and that all the win- 
dows were opened for about ten minutes, thus re- 
moving every particle of contamination.^'' That 
was her standard. 



lO THE VENTILATION 

Twenty years ago, fifteen years ago, and prob- 
ably not more than ten years ago, the Public 
Schools of New York were almost without ventila- 
tion. At the present time, however, whatever may 
be said against the school system of New York, it 
cannot be said that they are not making a most 
determined effort to secure a good standard of pu- 
rity in the air of the rooms. QWe may differ with 
them in their methods, and be disappointed in the 
results sometimes obtained, but nevertheless, the 
present management deserve the highest commen- 
dation for their efforts. 

PBTTENKOFER'S EXPERIMENTS. 

Pettenkofer has demonstrated by careful scien- 
tific cabinet experiments on an individual, 28 years 
of age, whose weight was 132 pounds, the amount 
of carbonic acid that the person would add to the 
atmosphere in which he lived and breathed in a 
given time. 

He found that "in repose " the individual added 
.00424 cubic feet of carbonic acid per hour (reduced 
to the volume of 32 degrees Fahrenheit) /^r/^?^/;^^/ 



OF THE SCHOOL II 

weight of his body ; and that under what he con- 
sidered "gentle exercise,'' he added .0059 cubic 
feet (per hour per pound weight of his body) ; and 
that the amount reached .01227 for "hard work :" 
all of which reduced to correspond to a person 
weighing 142 pounds (assumed average weight of 
adult human beings) would amount to .6 cubic feet 
of carbonic acid for a person " in repose ;" .9 for a 
person at "gentle exercise;" and 1.8 per hour 
when doing ' ' hard work. ' ' 

A STANDARD OF PURITY. 

With the foregoing in view, what should the 
standard of purity be ? and the amount of air ad- 
mitted per person to maintain it ? 

Able authorities are of the opinion that when the 
CO2 is maintained at .0002 in excess of what is 
found in the outer air, that it is at least good ; in 
which case there will have to be admitted 3,000 
cubic feet of fresh air per person per hour while 
"in repose" 4,500 cubic feet for persons at " gen- 
tle exercise ; " and 9,000 cubic feet for persons at 
'' verv hard " or laborious work. 



12 THE VENTILATION 

This certainly seems to be a liberal standard to 
maintain, and the best authorities now seem to 
think it is ample in cold climates in winter, as the 
cost of ventilation must enter into the question, 
particularly when a great number of persons have 
to be provided for in comparatively restricted 
space, such as hospitals, schools, etc. 

It is customary in hospitals to provide for a min- 
imum admission of 3,000 cubic feet of air per bed 
per hour, with mechanical means of increasing the 
admission to 6,000 cubic feet of air per bed per 
hour, when it is deemed necessary. This amount 
of air (3,000 to 6,000 cubic feet per bed per hour) 
seems to cover the contingencies and insure a 
standard, in which the excess or coincident CO2 
will be about .0002. Of course, when half this 
qua itity of air is admitted, other things being the 
same, the increase of coincident CO2 will be 
doubled, and will become about 4 parts in 10,000. 

MASSACHUSETTS' LAW. 
Under what is known as the ''Massachusetts? 
Law," which provides for the admission of 1,800 
cubic" feet of air per hour per child in the 



OF THE SCHOOL. 13 

schools (without regard to weight,) the additional 
vitiation (carbonic acid) will be about .0003 CO2 
when the average weight is about 90 pounds, 
which, of course, secures what may be termed a 
£-ood standsLvd of purity, without an excessive cost 
of maintenance. 

PURE CARBONIC ACID NOT A VITIATION. 

This treatise does not intend to convey the idea 
that a certain percentage of the carbonic acid 
(CO2) in the air, in its pure state, is a vitiation, as 
from ,0002 to .0004 of CO2 is nearly always present 
in what is considered pure outside air, at least in 
the neighborhood of cities. It does imply, how- 
ever, that coincident CO2 or the carbonic acid 
added by the lungs within doors, is the measure of 
the vitiation, as in proportion to it all the other 
emanations from the animal system, such as aque- 
ous vapor, etc., must and do exist, and that by 
measuring the excess of carbonic acid, which is 
easily done, a comparative conception at least of 
|.he other contaminations can be formed. 



14 THE VENTILATION 

TEST FOR CARBONIC ACID. 

Careful tests for carbonic acid in the air should 
be made by a chemist or one who has made a study 
of the subject. A crude comparative test, however, 
can be made by a layman in the following manner: — 

Procure a jar of lime water, made by placing a 
small quantity of ordinary burned lime in a vessel 
of water. After it has slaked and stood for a time 
the excess of lime will settle, leaving a clear and 
pure lime water on the top. Decant the clear 
water and it is ready for use. 

Procure a large necked bottle and make two 
holes in the cork. In one hole place a tube running 
near to the bottom of the bottle, the other hole 
being open. Attach a small bellows to the open 
end of the tube. Go into the open air and force 
air into the bottle with the bellows until the water 
becomes turbid : counting the number of strokes of 
the bellows. Then enter the suspected room with 
a fresh bottle full of lime water and renew the ac- 
tion of the bellows until the water becomes as tur- 
bid as before : counting the strokes of the bellows. 
Then, if it is found that it takes only half as many 




Fig. I. 



OF THE SCHOOL. 15 

strokes of the bellows to produce the same result 
inside as it did outside, the general conditions may 
be assumed to be good and the amount of carbonic 
acid in excess can be reasonably supposed to be no 
greater than the original quantity of carbonic acid 
outside. If, however, one fourth the number of 
strokes of the bellows produced the same result, 
then there would be four times the quantity of car- 
bonic acid inside that there was outside, or three 
times as much " in excess. " 

The carbonic acid combines with the lime in the 
water and makes insoluble carbonate of lime. 
This, of course, is a crude method, but with prac- 
tice, fairly accurate estimates can be obtained. The 
bellows should be opened to its full capacity each 
time so that the measure will always remain the 
same. 

Figure i shows the arrangement I have describ- 
ed, and in the hands of a school teacher will furnish 
at least an approximation of the amount of vitiation 
in a class room. 

COST OF VENTlIvATION. 

What does ventilation cost? The person who 
has to provide ventilation for a crowded building in 



1 6 THE VENTILATION 

a cold country, has also to assume the responsibil- 
ity for the fuel bills, and were it not for this ques- 
tion of fuel, there is no reason whatever why we 
should limit ourselves in the amount of air passed 
into or through a building, up to a point of mak- 
ing it draughty. 

A pound of coal burned under a boiler is equiva- 
lent to warming 486,000 cubic feet of dry air, one 
degree Fahrenheit, when the initial temperature of 
the air is zero ; while at 14 degrees above zero, it 
will warm 500,000 cubit feet of air one degree : and 
at 70 degrees above, 562,000 cubit feet of air — in 
each case one degree Fahrenheit. 

This establishes the fact, therefore, that 500,000 
cubit feet of air (in round numbers) can be warmed 
one degree Fahrenheit for the cost of one pound of 
coal, or 5,000 cubit feet of air can be warmed 100 
degrees for the cost of one pound of coal. This is 
the fuel cost of ventilation. It follows the immut- 
able law of equivalents and cannot be changed 
materially. 

In the neighborhood of New York, it has been 
found that an average rise of temperature of about 



OF THE SCHOOL. 1 7 

40 degrees Fahrenheit is sufficient to cover the 
ranges for an ordinary winter ; and that an average 
of 50 degrees is sufficiently high for any point 
within the United States, so that the average 
amount of air that can be warmed by the burning 
of a pound of coal in the East, North, West and 
Middle States of the Union will be between 10,000 
and 13,000 cubit feet. 

With coal at $5.00 a ton of 2,000 pounds (a fair 
average for the whole United States) it will require 
20c per hour for fuel to maintain the warmth of 
every one million cubit feet of air passed through a 
building, taking one day with another throughout 
the winter. 

In the case of hospitals, in which the heating is 
to be maintained day and night, say through 180 
days of a year, the fuel for the same time will be 
$864 for every million cubic feet of air passed in 
an hour. This, of course, does not include interest 
on the plant, labor, service etc., which increases it 
to about $2,000. per season per million cubit feet 
of fresh air passed into the building every hour. 
As the plant grows larger this can be reduced to 



1 8 THE VENTII^ATION 

probably $1500. per year for each additional million 
cubit feet of air admitted per hour. This is the 
cost of ventilation for hospitals. 

This estimate will be considerably modified in 
the case of schools as of course the schools are not 
run continuously. The fuel cost per hour, how- 
ever, will remain about the same (20c for each 
million cubit feet of air passed through the build- 
ing). An eight room school will require about 
1,000,000 cubic feet per hour — during sessions — for 
all purposes, increasing at about the ratio of 100,000 
cubic feet of air per room as the school building 
becomes larger. 

HORSE-POWER REQUIRED FOR 
VENTILATION. 
When the power or heat required is expressed in 
horse-power, it is equivalent to about 33. 3 centen- 
nial horse-power {continuously) per million cubic 
feet of air warmed and passed through the building 
in an hour. 

HOW TO SECURE VENTILATION. 
The savage made a hole in the' roof of his house 
to let out the smoke. This was the first attempt 



OF THE SCHOOL. IQ 

at ventilation and very little improvement was 
made on this primitive method until about 600 
years ago when the fireplace and chimney appeared, 
and this sufficed for dwellings until abont Frank- 
lin's time, when he invented the ''aspirating stove;" 
the waste heat of which drew a measure of air out 
of the room : which air was renewed the best way 
possible, through window and door cracks and 
porous building materials. 

The early chimney was as a general thing so 
large that when the doors and windows were closed, 
the air to supply the fire came down one side of the 
chimney, while the smoke w^ent up the other side, 
and this circulation went on even after the fire was 
out (though in a subdued measure) ; thus securing 
"accidental ventilation." 

In the latter part of the 17th century systematic 
ventilation was undertaken by Sir Christopher 
Wren in the British House of Parliament, London. 
It was a little better than "some holes in the 
ceiling." 

About 1723 Desaguliers improved the foregoing 
system by connecting the holes or tubes with heated 



20 THE VENTII^ATION 

chimneys. This is the first well authenticated 
account of ventilation by "heat aspiration." 

About the year 1736 Desaguliers again improved 
the ventilation of the British House of Parliament 
by the use of centrifugal fans, which were very 
similar to the "housed" pressure fan or blower of 
to-day. This is probably the first well authenti- 
cated account of the use of "pressure" and "ex- 
haust" fans to buildings. 

It is only within the last forty years, however, 
that a great and well defined stride has been made 
in the development of systematic ventilation for 
habitations. The little that had been done by 
persons previous to that time was in special cases 
and only in notable buildings, such as the Capitol 
at Washington and some hospitals and asylums, 
and it is probable that General Arthur Morin, Di- 
rector of the Conservatory of Arts and Trades, 
Paris, was the first to disseminate and give a clear 
understanding, in his writings, of the true princi- 
ples of modern systematic ventilation, and I suggest 
for the consideration of all students a translation of 
his work on " Warming and Ventilation in Occu- 



OF THE SCHOOL. 



21 



pied Buildings," a translation of which by Mr. Clar- 
ence B. Young, appeared in the annual reports of 
the Board of Regents of the Smithsonian Institute 
for the year 1873 and 1874. 

He recommended as the amount of air to be 
changed every hour to preserve the healthful con- 
dition of the room, as follows : — 

Hospitals : 

For ordinary cases of sickness 
For surgical and lying-in cases 
During epidemics . 

Prisons 

Workshops : 

Ordinary occupations 
Unhealthful occupations 

Barracks : 

During the day 

At night .... 

Theatres ..... 
Assembly-rooms and halls, for long 

receptions .... 

Halls for brief receptions ; lecture 

rooms. .... . 1,059 

Primary Schools .... 42 — 4,530 

Adult Schools ..... 833 — 1,059 



Cubic Feet. 

2,119—2,472 

3,532 

3,709 

1,766 

2,119 
3,532 

1,059 
1,413—1,766 
1,413—1,766 

2,119 



2,2 THK VKNTIIvATION 

I am unable to say why he placed a higher pro- 
portion of air for primary schools than for adult 
schools. It may be an error of the translator's. 

It will be noticed that his quantities of air do 
not fall so far below what is considered very fair 
practice of the present day. 

MIXING THE AIR— OR MIXING VALVES. 

Morin was probably the first to point out the im- 
portance of keeping the quantity of air admitted to 
a building constant^ while making its temperature 
variable ; the variations in temperature being to 
suit the changes in the outside temperature. 

The only general method in vogue previous to 
about 20 years ago was to close the register when 
the room was sufficiently warm ; which, of course, 
not only cut off the heat supply, but the air supply 
as well, interrupting the fresh air supply and 
nullifying ventillation. 

This, however, is changed now in many build- 
ings that are systematically ventilated. 

General Morin called attention to the necessity 
of the " mixing valve " in the following words : 



OF THE SCHOOL. 23 

"During the period of artificial heating, it is 
proper to reserve means of mixing with the warm 
air, supplied with the heating apparatus, cool air, 
the amount of which may be regulated by conven- 
ient registers. For this purpose the warm air sup- 
plied by the heating apparatus should be received 
in a special register or mixing-chamber, into which 
the cold air should also enter before passing into 
the distributing pipes." 

The usual method of accomplishing the fore- 
going, now followed in the United States, is shown 
in the cut. (Figure 2 and Figure 2'). 

The dampers "b" "b" are connected with a 
rod and operated from the room by hand-pulls, or 
automatically operated by pneumatic pressure con- 
trolled by a thermostat. 

Various modifications of this method of mixing 
warm and cold air are in use; and those intro- 
duced here are ^simply to show the principle in- 
volved. 

WARMING AND VENTILATION OF A 

SCHOOL. 
The usual school room for from 40 to 50 pupils, 
as now commonly designed, has a floor space 



24 THE VENTILATION 

of about 24 feet by 32 feet, with light on at least 
two sides of the room ; the general endeavor being 
to have the sitting so arranged that the light will 
come in over the left shoulder of the pupil. A 
sketch of such room is shown in Figure 3. 

Provision should be made for the admission of at 
least 100,000 cubic feet of fresh air to one such 
room in an hour. It may be that it will not all be 
required, even to comply with what is known as 
the "Massachusetts' I^aw," (30 cubic feet per child 
per hour.) 

The admission of this air should be above the 
head-line, and one inlet register is sufficient. 

Experiments have demonstrated that the neces- 
sary flue for such a room should have a cross sec- 
tion of not less than 3 feet in its smallest part, and 
that 4 feet is probably the limit required, the latter 
being the size now adopted by the writer. 

It is the custom in New York City schools to 
leinforce the warm air system by a direct system, 
the object being to maintain the heat of the room 
by direct radiation when the fans are not running. 




y CLOAK-ROOM 



^ 



OF THE SCHOOL. 25 

such as at night, etc. , using the fans only during 
the hours of school. 

It has been found that when a quantity of air 
equal to 100,000 cubic feet is admitted to an ordin- 
ary school room in an hour, that this amount of 
air can be admitted and withdrawn without appre- 
ciable draughts, at a temperature sufficiently low 
to prevent the room from being overheated. Under 
this condition of ample quantity and low tempera- 
ture, it has been found, except in exceedingly cold 
parts of the United States, that direct radiation can 
be dispensed with and still give comfortable condi- 
tions at all parts of the room. 

It is not desirable, however, from a point of 
economy of maintenance, to admit such large 
quantities of air when the school is not in session ; 
therefore, in the construction of a heating and ven- 
tilating apparatus for a school, it is desirable either 
to provide a reasonable quantity of direct radiation 
or to design the flues and the indirect portion of 
the heating apparatus in such a manner that suffi- 
cient air will pass through the flues by natural 
draught to maintain the heat when the school is 



26 THE VENTILATION 

not in session, but with a greatly reduced quantity 
of air and with a very much increased temperature 
above what is necessary when the school is in 
session. 

A register of 50^ greater area than the cross sec- 
tion of the air flue, when placed above the head- 
line, the lower edge being 7 to 8 feet from the floor, 
will not cause inconvenience as long as the tem- 
perature of the entering air is above the air of the 
room, although the velocity of the air may be 4 or 
even 5 feet per second. 

In the matter of withdrawing air from a school 
room, the air should be taken from as near the floor- 
line as possible, and preference should be given to 
a register that will 'be low and wide rather than the 
reverse. Building construction, of course, some- 
times interferes with the proper shaped flue to 
secure the best results. The architect, however, 
should endeavor to make the flues wide, so that 
the register can be low, and no objection should be 
made to having the register partly in the base- 
board, as appearance should give way to utility in 
schools. 



OF THE SCHOOL. 27 

The lower or "floor vent registers" can be in 
the same wiall or group as the heat registers with 
the outlet at the floor, and it is probably the best 
position for them. 

The question of ceiling ventilation and ceiling 
or upper side wall registers in a school room is a 
very unsettled one. In winter time, it is probably 
unnecessary to have them, although this does not 
always satisfy, and for this reason it is customary 
to place another ventilating register in the same 
vent flue as the floor register but near the ceiling. 
This brings the ceiling outlet too close to the inlet 
or heat register, resulting in robbing the room of 
its heat, and the "short-circuiting" of the fresh 
air current when the upper register is open. For 
this reason perhaps it would be well to have a 
double set of vent registers and vent flues to each 
room when possible ; the lower vent registers being 
placed near the floor in the flue group with the 
heat flues, and the upper vent registers near the 
ceiling in another group remote from the heat. 
This will admit of both floor and ceiling ventila- 
tion at the same time. It will also prevent the 



28 THK VKNTII^ATION 

intensity or draught of the Floor '' vent " from be- 
ing interfered with when the upper vent is opened, 
and it will prevent short-circuiting to a very great 
extent. 

All schools designed for forced ventilation should 
also be arranged so that in case the forcing or fan 
mechanism gets out of order, that air and heat suf- 
ficient will still enter the rooms by natural meth- 
ods to keep them comfortably warm, so that it will 
not be necessary to dismiss the school through 
temporary injury to the fan or motor. 

Figure 3 shows the ground plan of a typical 
school room, arranged for seating from 40 to 50 
pupils ; and the object of introducing these dia- 
grams here, is to discuss the question of a standard 
relation between the school room and its warming 
and ventilation. 

The tendency lately is to provide what may be 
called a " breathing wall." This wall may be on 
the long or the short side of the room, though pre- 
sumably it is best to have it on the short side and 
the wall between the school room and the cloak 
roomlis best taken for this purpose. If it can be 



OF THE SCHOOL. 29 

arranged by the architect that it is not a construc- 
tion wall, all the better. 

When this wall is used, easy access is obtained 
for the warm air through the flues to both the 
school room and its corresponding cloak room, as 
shown by the arrows ; the flues simply opening on 
opposite sides of the same wall. 

When the wall "a" is used as a " breathing " 
or flue wall, as occasionally happens, it complicates 
the entire matter by having to carry both heat and 
vent flues across the cloak room, and for this reason 
alone it should not be used as a/' breathing wall." 

An advantage also of using the wall between the 
cloak room and the school room as the breathing 
wall is that the space underneath the lower cloak 
room can be taken as a heating chamber, or if 
there is any reason why this room cannot be used 
as a heating chamber, the heating chamber can be 
constructed on the opposite side of the wall by tak- 
ing a portion of the basement room usually used as 
a play room or for toilet rooms. 

Reference to Figure 4 will show the arrangement 
of the radiators or heaters required for a two-story 



30 THE VENTILATION 

school building. There is sufficient room, how- 
ever, in the ordinary breathing wall to carry ample 
flues for three stories, but that is about the limit 

for the size flues required for ordinary school 
rooms. 

For a two-story school, it is necessary to find 
room for four large flues, aggregating not less than 
3 square feet each, and for four small flues (two 
heats and two vents) the large flues for the school 
rooms and the small flues for the cloak rooms. 

Another story will about take up the remaining 
blank space in the flue walls, requiring, of course, 
a rearrangement of t^^e flues as shown here. 

Flue Hj (Figure 3) shows the heat flue for the 
first story, and alongside of it is flue H2 which 
sends warm air to the second story. Their relation 
to the radiators is shown m Figure 4. 

The small flues H2 and Hj show the flues in 
their relation to the cloak rooms. 

The flues V, in like manner (Figure 3) show the 
main ventilating flues, Vj being the first story flue, 
and V2 the second flue. 

I will say that the second story vent does not 
run down, as shown in Figure 3,lbut the space in 




1 



OF THE SCHOOL. 31 

the wall is required for it, and sometimes the un- 
der part of it is used as a heating flue so as to save 
wall space. 

Figure 5 is a simple section through the base- 
ment and first floor of the same school building, 
showing the relation of the heating chamber to the 
hot air flue, with the radiator, cold air duct, and 
the position of the hot air or inlet register (the 
lower edge of which is now always placed above 
the head-line.) To determine the height of the 
register, one wants to be guided by two conditions : 
(i) that the register must be sufficiently far above 
the head-line so the air will not inconvenience 
one, and (2) to be sufficiently far from the ceiling 
to prevent a dark streak which soon appears there- 
on (caused by the invisible dust carried in with 
the fresh air), when the register is very close to the 
ceiling. 

Figure 5 is a vertical section through the hot air 
duct, the fresh air inlet " F. A.," showing how 
the air passes to the radiator to be warmed, and 
through the upper part of the switch valve, thence 
through the flue to the register. 



32 THE VKNTII.AT10N 

When the room is sufficiently warm, the switch 
valves "d " and " d' " change their position so that 
^' d " is closed and " d' " is open, when the passage 
of air will be through the lower valve, thus permit- 
ting cold air to pass into the room. 

By fixing these valves "d" and " d' " at any in- 
termediate position, mixed air will pass up the flue, 
usually at a little above 70 degrees, keeping the 
room at the constant and desired temperature. 
When these contrivances (switch valves) are auto- 
matically operated by a proper system of thermos- 
tatic control, the variations of a class room can be 
kept within 2 degrees Fahrenheit. 

Figures 2 and 2' show modifications of the switch 
valve ; Figure 2 showing a good arrangement of 
valve as automatically controlled, while Figure 2^ 
shows the hand-controlled swatch valve. It is 
nothing but a piece of sheet iron fastened in the 
flue at the point shown and arranged to be drawn 
against the upper opening by a hand-pull within 
the school room. The valve divides the flue so 
that cold air from below can pass up and mingle 
with the warm air from above the radiator, and 



OF THE SCHOOL. 33 

thus pass into the room. The objection to the 
hand-controlled mechanism, however, is that the 
teacher and those concerned will never think of 
adjusting it until the room becomes, I will say, a 
little too warm, and that again they will not think 
of changing it until the room becomes a little too 
cold, so that it is alternately a little too hot and a 
little too cold, to the annoyance and discomfort of 
all concerned. The theory is right, but the prac- 
tice is wrong, and the only relief from the annoy- 
ance of it, is automatic control, which practically 
anticipates the requirements of the room. 

Figure 2 shows the clean-out at the bottom of 
the flue, which is very necessary. 

Figure 6 is a vertical section through the same 
wall as Figure 5. This section, however, is through 
the vent flue Vi (Figure 3) while Figure 5 is a ver" 
tical section through the heat flue Hi (Figure 3.) 

Figure 6, therefore, is a vertical section through 
the main vent flue of the school room, and the 
heat and vent flues are shown in separate illustra- 
tions rather than in the conventional manner so as 
to overcome confusion of ideas, if possible ; Fig. 
5, being the section through the heat flue. 



34 'THE VENTILATION 

I might say that the pink, of course, in the il- 
lustration, indicates heat, and that the green indi- 
cates foul or vitiated air, while the blue indicates 
fresh air, or air that is relatively cold, such as at 
the windows. Red also represents the primary 
source of heat, or the radiators. 

The ordinary course, therefore, of the fresh air, 
is from the inlet through the radiator and through 
the flue to the room, thence making a circuit to 
the windows and becoming lightly cooled, (indi- 
cated by blue,) thence passing to the floor and be- 
coming vitiated and passing out at the flues marked 
in green, Figure 6. 

The warm air as it leaves the register will rise 
to the ceiling and expand and flow out under the 
same ; the windows of the building supplying the 
power to keep up the circulation within the room, 
and they perform a very important function in the 
mixing of the air. The glass of each window be- 
ing cooler than the temperature of the internal air, 
made so by the temperature of the external air, 
causes the downward movement of the air to the 
floor, across which it flows to the point of outlet. 
Every child within the room also becomes a factor 
for air moving. His or her body is warmer than 
the air so that there is an upward current of air at 
each child, and this upward current carries the 






OF THE SCHOOL. 35 

exhalations with it to the ceiling, there to mix with 
the warm fresh air, flow across the ceiling to the 
various w^'ndows, down at each window, and across 
the floor towards the outlet. It may be said that 
the child is breathing the floor air, which is passed 
to the ceiling over its body, and this to a great ex- 
tent is true ; but the question must here be asked, 
"is this floor air foul?'' and it may be answered 
in the negative, so long as it is known that a 
reasonable per capita of fresh air has been admitted. 

It is utterly impracticable to bring fresh air 
directly to the lungs of each child or person in a 
crowded or partially crowded room, and all that is 
practicable is to admit sufficient fresh air per person 
to secure a dilution or standard of purity which is 
reasonably good, and which in fact, can be made 
very good if sufficient fresh air is admitted. 

The conditions in any school room are analogous 
to admitting a tiny stream of ink to a reservoir of 
water, while at the same time you admit a very 
large ^quantity of pure water to the same tank, 
allowing an equal quantity to overflow. If there 
are any fish in this tank, it is possible, by admit- 



36 THE VENTILATION 

ting sufl&cient pure water, to keep them in good 
health, and they will not be poisoned by the small 
stream of ink, provided the water in the tank is 
kept well agitated ; and in the case of the school, 
the cold of the windows and the heat of the bodies 
of the children are the agitators. These two forces 
produce an agitation which keeps the mixture at a 
nearly constant and equal condition of freshness 
(or foulness), at every part of the room. 

There seems to be an idea that it is preferable to 
have the heat flue as near the outside wall and 
windows as possible, and that the vent flue should 
be as near the inside or warm corner of the room 
as possible. I am not convinced that much is 
gained in choice of positions. When the heat flue 
is near the outside wall, the air is projected along 
the wall and made to turn at the short side of the 
room, and in that way to help the circulation. It 
may be claimed there is an inert patch at the ceil- 
ing in the warm corner of the room if this is carried 
out. If such is the fact, then it would be better 
to have the inlet or hot air flue in the warm corner 



OF THE SCHOOL. 37 

of the room, as it would be the means of stirring 
up this inert patch. 

These ideas are put forth because we are apt to 
find persons arguing from both sides of this ques- 
tion, and my own opinion is that there is very little 
gained or lost, no matter what relative positions 
the inlets and the outlets have, provided the outlet 
or vent is pretty near what may be called the warm 
comer of the room. 

When 100,000 cubic feet of air are admitted 
through the hot air flue Hj in an hour, and drawn 
out through the vent flue Vi in the same time, it 
is very reasonable to assume that the conditions 
within that school room are good, and when this 
quantity of air is passed through a school room, 
not only will the air be kept at a fair standard of 
purity, but an equality in temperature will be 
maintained so nearly alike between the ceiling and 
the floor that they will not vary 4 degrees, and this 
in the outer corner of the room at "X," in what 
may be called the focus of two windows. 

When large quantities of air at low temperatures 



38 THE VENTII^ATION 

are admitted to a room, a wonderful uniformity of 
temperature is the result. 

When small quantities of air are admitted, at 
high temperatures, great uneven ness of tempera- 
ture prevails. 

When large quantities of air are admitted to a 
room, such as will be required in a school room, if 
one puts his hand over the inlet register, the 
temperature of the air will feel cool to the touch. 
This is because the air is coming in considerably 
below the blood temperature, but still sufficiently 
high to maintain the temperature of the room. If 
it came in at a higher temperature, it would simply 
overheat the room, and either the temperature or 
the quantity of air admitted would have to be 
lessened. 

Supplementary direct radiation is sometimes 
used in school rooms, usually in the form of a coil 
of 2 or 3 pipes placed on the outside walls under 
the windows. 

There are two reasons for these coils. They 
may be necessary in very cold or exposed places so 
as to prevent too great a down draft at the win- 



OF THE SCHOOL. 39 

dows, but this interferes with air mixing and diffu- 
sion, as it reverses the window current. The other 
reason is on account of the extreme expense of 
maintaining the heat of a school building at all 
times by indirect radiation. In other words, an 
attempt is made to use the indirect radiation and 
ventilation during the school session, and to keep 
the building warm or partially warm at night by 
the direct coils. This, however, is hardly ever 
carried out, and the alternate use of coils at night 
or in the early morning and afternoon, and ventila- 
tion during the school hours becomes a dead letter, 
as it will not be properly attended to, so that there 
is nothing but a confusion of the heating system 
and general annoyance. 

For this reason it is better, when possible, to 
omit the direct radiation from a school room. If 
it is used, it should never be used except in con- 
nection with an automatic shut off system. 

It is necessary, however, to practice economy in 
the warming of schools, for should the ventilating 
system be run during the 24 hours, or even during 
16 hours of each day, the cost of warming the 



40 THE VENTILATION 

school is either doubled or trebled, as the case may 
be. This is a great cause for complaint with 
schools : — the fuel bill is simply enormous, as the 
full million or two million or three million cubic 
feet of air (according to the size of the school) that 
is admitted each hour, has to be warmed from the 
outside to the inside temperature, and then allowed 
to escape at the latter temperature, tending to 
warm all out-of-doors. 

This can be avoided, however, to a very great 
extent, by providing an internal or night circula- 
tion. This is rarely carried out in its entirety, 
though a modification of it is sometimes used, 
whereby the cold air inlets and the ventilating 
outlets are all closed ; the class room doors opened, 
so that the air from the class rooms is allowed to 
pass down through the halls and stairways to the 
basement, and enter the chambers through a door- 
way from the hall, as at "b.'* Fig. 4. 

This, however, has its disadvantages as some 
rooms will warm and some rooms will not, due to 
local conditions. 

To insure inside or night circulation, therefore, 



OF THE SCHOOL. 4I 

in its best form, there should be a night circulating 
flue arranged from each room. This is shown by 
dotted lines in Fig. 5 and by blue on Fig. 7 which 
latter is a section through this flue. It is best ar- 
ranged so as to start on a cold side of the room, 
as shown in Figure 3 at "c." It drops to the 
basement, as shown in Figure 7, and passes un- 
der the basement floor, returning to the heating 
chamber as shown by the flue lines and ar- 
rows. At this time, the fresh air inlet (F. A.) is 
closed and the regular vent flues 'shown in Fig. 6 
are closed so as to prevent the escape of heat or 
air in that direction. It will be noticed by Figure 
7 that one operation from each school room can be 
made to accomplish this result, by the use of a pull. 
In the vent flue there are three dampers, arranged 
on a single pull. The dampers are shown in what 
might be called the "night position." In other 
words, the regular ventilating flues are shut off" and 
the night or internal circulation flue is opened. 
The janitor, or some one appointed for that pur- 
pose, should enter the room at a few minutes before 
9 o'clock in the morning, unhook the pull from 
the wall and drop the dampers until they assume 



42 THE VENTILATION 

the position shown in Figure 6, when full ventila- 
tion is obtained for the day session. 

I consider the drawings here shown to be a fairly 
full expositionof the most recent principles involv- 
ed in school room ventilation. They are the result 
of experience^ and all those who have made a study 
of the question are gradually being forced to the 
same conclusions. 



Card by the Author. 

THE author offers his services as an Expert and Designer 
of heating, cooling and ventilating plants, power houses 
and general engineering. 

He has had thirty years experience, both practical and the- 
oretical, with a thorough knowledge of all the minutia of detail 
of construction. His experience enables him to assure econ- 
omy, both in design and maintenance. 

Below are a few of the buildings for which he has furnished 
plans, specifications, etc. 

OFFICE BUILDINGS. 

Manhattan Co.'s & Merchants' Bank Building, New York. 

' ' Number Seven Wall Street, ' ' New York. 

' ' Robert Hoe ' ' Building, Broadway, New Y'ork. 

Malley Building, New Haven, Conn. 

Temple Bar Building, Brooklyn, N. Y. 

Mechanics Bank, Brooklyn, New York. 

Hanover Fire Insurance Co.'s Building, New Y'ork. 

Lawyers' Title Insurance Co.'s Building, New Y'ork. 

Washington Building, New Haven, Conn. 

Winchester Building, New Haven, Conn. 

Exchange Building, New Haven, Conn. 

Clayton Block, Denver, Colorado. 

The Metropolitan Telephone & Telegraph Co.'s Building, New Y'ork 

Chusman Building, Denver, Colorado. 

Southern New England Telephone Co.'s Building, Bridgeport, Conn. 

Joseph Butteuweiser Building, New York. 

Tribune Building, New York. 

GOVERNMENT BUILDINGS. 

Ellis Island U. S. Immigrant Station, N. Y. Harbor. 

U. S. Immigrant Hospital, N. Y. Harbor. 

U. S. Immigrant Baths, N. Y'. Harbor. 

U. S. Immigrant Dormitories, N. Y'. Harbor. 

U. S. Army Mess Hall, David's Island, N. Y. Harbor. 

TJ. S. Army Barracks, David's Island, N. Y'. Harljor. 

Marine Barracks, Navy Yard, Brooklyn, N. Y. 

INSTITUTIONS. 

New York State Reformatory, Elmira, N. Y. 
Military Academy, Peekskill, N. Y. 
Insane Asvlum, Wilmington, Del. 

(43) 



44 A CARD TO THE PUBLIC. 

County House, Hares Corners, Del. 

Madame De Hirsch Home for Working Girls, New York. 

Hebrew Orphan Asylum, Brooklyn, N. Y. 

Home for Aged & Inform Hebrews, New York. 

Leake & Watts Orphan Asylum, New York. 

Hebrew Orphan Asylum, Newark, N. J. 

SCHOOLS. 

Vanderbilt Memorial, Yale University, New Haven, Conn. 

George Street Public School, New Haven, Conn. 

Norton Street Public School. New Haven, Conn. 

Public School No. 3, Paterson, N. J. 

St. Agnes' School, Brooklyn, N. Y 

Holy Family School, New Bedford. Mass. 

Phelps Memorial (Yale University) New Haven, Conn, 

Peekskill Military Academy, Peekskill, N. Y. 

State School, Cold water, Mich. 

Trinity School, New York. 

Locust Valley Public School, L. I. 

Hicks ville Public School, L. I. 

Roslyn Public School, L. I. 

Glen Road Schoo', Boston, Mass. 

Blairsville Ladies' Seminary, Blairsville. Pa. 

St. Mary's Parish School, Charlestown, Mass. 

RESIDENCES. 
Hon. William A. Clark's Mansion (Fifth Avenue) New York. 
Mr. Charles W. Clark's Residence, Butte, Mont. 
Mr. Howard B. Tattle, Naugatuck, Conn. 
Mrs. B. T. Williams, Hartford, Conn. 
Mr. H. H. Cook (Fifth Avenue) New York. 
Gen. F. R. Halsey (53rd Street) New York. 
Mrs. Edward Perkins, Hartford. Conn. 
St. Luke's Rectory, Brooklyn, N. Y. 
Mr. H. B. Hollins, Islip, N. Y. 
Mr. W. Bayard Cutting, Oakdale, N. Y. 
Dr. John N. Tilden, Peekskill, N. Y. 
St. John's Rectory, Elizabeth, N. J. 
Dr. Fredk. Hyde, New York. 

Y. M. C. A. BUILDINGS. 

Y. M. C. A. Building, New Haven, Conn. 
Y. M. C. A. Building, Des Moines, Iowa. 
Y. M. C. A. Building, Cleveland, Ohio. 

PRINTING HOUSES. 

New York Realty Co.'s Building, Rose Street, N. Y. 
H. C. Hallenbeck, Pearl & Park Streets, New York. 

HOSPITALS AND MEDICAL BUILDINGS. 

The (new'* College of Physicians and Surgeons of the City of New York^ 
Vanderbilt College, now Medical Department of Columbia University, 

L.ofC. 



A CARD TO THE PUBLIC. 45 

The Sloane Maternity Hospital, (old and new) New York. 

The Vanderbilt Clinic. New York. 

New Laboratory, College Physicians and Surgeons, N. Y. 

Wm. J. Syms Operating Theatre, (Roosevelt Hospital) N. Y. 

Columbia College Medical I»epartinent (westerly extension) Bacteriology. 

Clinical Building, Yale Medical Department, New Haven, Conn. 

Immigrant Hospital, Ellis Island, New York Harbor. 

Orthopedic Hospital, New York. 

Columbia College Medical Department, (easterly extension) Museum Bldg 

Insane Asylum, Kalamazoo, (Sup ) Michigan. 

Maternity Hospital, New Haven, Conn. 

Newark City Hospital, Newark, N. J. 

DRY GOODS STORES. 

Messrs. Abraham & Straus, Great Department Store, Brooklyn, N. Y. (1898). 

The W. & J. Sloane Carpet Store, New York. 

Le Boutiller's Dry Goods Store, 23rd Street, New York. 

Astor Estate Building, 552, 554, 556 Broadway, N Y. City. 

Swan Building, 339 Broadway, New York. 

Easterly Extension Abraham & Straus' Department Stores. Bklyn. (19(X)). 

" Edward Malley Co.'s Department Store,' ' New Haven, Conn. 

Mendel & Freedman Department Store, New Haven, Conn. 

W. & J. Sloane (new) Building, 19th Street, (1898) New York. 

Abraham & Straus' Power House, (2000 H. P.) Brooklyn, N. Y. 

THEATRES. 

American Theatre, New York. 

Public Theatre, Ogdensburg, New York. 

Music Hall, New Haven, Conn. 

CHURCHES. 

Cong. Shearith Israel Synagogue, New York. 

All Angels P. E. Church, New York. 

St. Francis Xavier (R. C.) Church, Brooklyn, N. Y. 

Baptist Church, New York. 

Mormon Temple, Salt Lake City, Utah. 

St. Luke's P. E. Church, Brooklyn, N. Y. 

Temple Mishkan Israel Synagogue, New Haven. 

St. Agnes' Church & School Buildings, Brooklyn, N. Y. 

FACTORIES. 

Lemair Schwartz Factory Building, N. Y. 

Bamford Mill, Wilkesbarre, Pa. 

Barber Underwear Factory, Peekskill, N. Y. 

Reed & Carnrick's Chemical Factory, Jersey City, N. J. 

American Stone Co.'s Plant, Portland, Me. 

Haines Piano Factory, N. Y. 



46 A CARD TO THK PUBI^IC. 



BANKS. 

The Importers' & Traders' Bank, New York. 
Manhattan Co.'s Bank, New York. 
Merchants' Bank, New York. 
Astor Bank, New York. 
Mechanics Bank, Brooklyn, N. Y. 

COURT HOUSES. 

Livingston County Court House, Geneseo, N. Y. 
St. Lawrence County Court House, Canton, N, Y. 

PRISONS. 

New York State Reformatory, Elmira, N. Y. 
State Prison, Ionia, Michigan. 
State Prison, Jackson, Michigan. 
County Jail, St. J^awrence Co., N. Y. 

LIBRARIES. 

Carnegie Library, Atlanta, Ga. 
Torrington Library, Torrington, Conn. 



Hundreds of other large buildings and residences throughout the United 

States. 
Consulting Engineer Electric Subway Companies, N. Y. 
Mechanical Engineer Empire City Subway Company, N. Y. 

iTERMS FURNISHED ON APPLICATION. 



\HE Author is the pioneer writer in 
America on the suhjeot of Steam 
Heating. 

His work "BALDWIN on HEATING," 
has reached the 16th edition. Price $2.50. 

His work "HOT WATER HEATINQ 
AND PITTING " is in the 3rd edition. 
Price, $2.50. 

His " BLUE BOOK " is Data for Heating 
and Ventilation. Price, 50 cts. 

His "RED BOOK" is An Outline of 
Ventilation and Warming. Price, $L00. 

They are standard American works of 
reference on these subjects. 



J^ 



•\ 1909 



SEP 2B jpj- 



!£sr%t 



LIBRARY OF 



CONGRESS 



0020975^52* 



